I tried the ADF and I couldn't replicate the problem, but only with the savestate (and very seldom).
So this too is a timing issue like that of the ball "shadow".
(I didn't check what part of the code could be the cause :))

The savestate was done with Quickstart A1200 + 8MB fast only, nothing strange ( = a basic A1200 + 8MB Zorro II fast)... so this game unfortunately looks just badly written as far as (cpu?) timing routines is concerned. I remember I had excessive interlaced bouncing effect also on my real Blizzard A1200 @66Mhz, but probably with emulation and a 144Hz LCD screen is even more visible.

P.S.
I'm not a big fan of Pinball Illusions anyway, so... ;)